Depending on motor's applications and user's needs, a motor control strategy may have different objectives. Motors may be controlled to achieve maximum torque, maximum torque per ampere, minimum core loss, maximum efficiency for a given combination of torque and speed, minimum torque ripple for a given combination of torque and speed, maximum constant power speed ratio (CPSR), or other objectives.
For example, recent advances in high-energy batteries, combined with the development of smaller and more powerful motors for electric vehicles, portable appliances and electronic equipment, emphasize the need for a high-efficiency motor control scheme to achieve low power consumption in order to extend battery life, providing longer hours of operation. However, in some applications, such as vehicle driving operation, there may be a need for torque capability in excess of that available from the most efficient motor control scheme. A driver may demand higher torque than the system can accommodate with the high-efficiency motor control scheme. In servo control applications, or when smooth control is required at lower speeds, minimizing the torque ripple becomes the main issue for a control strategy. For control of motors that require wide ranges of constant power operations, such as adjustable-speed driving motors, it is necessary to achieve high constant power speed ratios in the vicinity of 10 or even higher.
Motor control parameters may be optimized to achieve desired objectives. However, variable conditions of motor operation and changing motor's parameters call for frequent re-evaluations of motor control parameters optimized to achieve certain objectives. The need thus exists for a motor control system able to adaptively optimize motor control parameters during motor operation.